Frontal impacts are the number one killer of vehicle occupants in automobile accidents with about 16,000 fatalities each year. Side impacts are the second cause of automobile related deaths with about 8,000 fatalities each year. The number of fatalities in frontal impacts is now decreasing due to the introduction of airbags and mandatory seatbelt use laws. It is natural now that a considerable effort be applied to saving lives in side impacts.
Several automobile manufacturers are now considering the use of side impact airbags to attempt to reduce the number of people killed or injured in side impacts. The side impact problem is considerably more difficult to solve in this way than the frontal impact problem due to the lack of space between the occupant and the side door and to the significant intrusion of the side door into the passenger compartment which typically accompanies a side impact.
Some understanding of the severity of the side impact problem can be obtained by a comparison with frontal impacts. In the Federal Motor Vehicle Safety Standard (FMVSS) 208 49 kph crash test which applies to frontal impacts, the driver, if unrestrained, will impact the steering wheel at about 30 kph. With an airbag and a typical energy absorbing steering column, there is about 40 cm to about 50 cm of combined deflection of the airbag and steering column to absorb this 30 kph difference in relative velocity between the driver and vehicle interior. Also, there is usually little intrusion into the passenger compartment to reduce this available space.
In the FMVSS 214 standard crash for side impacts, the occupant, whether restrained or not, is impacted by the intruding vehicle door also at about 30 kph. In this case there is only about 10 to 15 cm of space available for an airbag to absorb the relative velocity between the occupant and the vehicle interior. In addition, the human body is more vulnerable to side impacts than frontal impacts and there is usually significant intrusion into the passenger compartment. A more detailed discussion of side impacts can be found in a paper by Breed et al, xe2x80x9cSensing Side Impactsxe2x80x9d, Society of Automotive Engineers No. 940651, 1994, which is included herein by reference.
Ideally, an airbag for side impact protection would displace the occupant away from the intruding vehicle door in an accident and create the required space for a sufficiently large airbag. Sensors now being used for side impact airbags, however, begin sensing the crash only at the beginning of the impact at which time there is insufficient time remaining to move the occupant before he is impacted by the intruding door. Even if the airbag were inflated instantaneously, it is still not possible to move the occupant to create the desired space without causing serious injury to the occupant. The problem is that the sensor that starts sensing the crash when the impact has begun, is already too late, i.e., once the sensor detects the crash, it is usually too late to properly inflate the airbag.
There has been discussion over the years in the vehicular safety community about the use of anticipatory sensors so that the side impact accident could be sensed before it occurs. Heretofore, this has not been practical due to the inability to predict the severity of the accident prior to the impact. A heavy truck, for example, or a tree is a much more severe accident at low velocity than a light vehicle or motorcycle at high velocity. Until now, it has not been possible to differentiate between these different accidents with a high degree of certainty.
Once a sufficiently large airbag is deployed in a side impact and the driver displaced away from the door and the steering wheel, he will no longer be able to control the vehicle that could in itself cause a serious accident. It is critically important, therefore, that such an airbag not be deployed unless there is great certainty that the driver would otherwise be seriously injured or killed by the side impact. Anticipatory sensors have heretofore not been used because of their inability to predict the severity of the accident. As discussed more fully below, the present invention solves this problem and therefore makes anticipatory sensing practical. This permits side impact airbag systems that can save a significant percentage of the people who would otherwise be killed as well as significantly reducing the number and severity of injuries. This is accomplished through the use of pattern recognition technologies such as neural networks such as discussed in co-pending patent application Ser. No. 08/640,068 filed Apr. 30, 1996 which is a continuation of U.S. patent application Ser. No. 08/239,978 filed May 9, 1994, now abandoned.
Neural networks are capable of pattern recognition with a speed, accuracy and efficiency heretofore not possible. It is now possible, for example, to recognize that the front of a truck or another car is about to impact the side of a vehicle when it is one to three meters or more away. This totally changes the side impact strategy since there is now time to inflate a large airbag and push the occupant out of the way of the soon to be intruding vehicle. Naturally, not all side impacts are of sufficient severity to warrant this action and therefore there will usually be a dual inflation system as described in more detail below.
Although the main application for anticipatory sensors is in side impacts, frontal impact anticipatory sensors can also be used to identify the impacting object before the crash occurs. Prior to going to a full frontal impact anticipatory sensor system, neural networks can be used to detect many frontal impacts using data in addition to the output of the normal crash sensing accelerometer. Simple radar or acoustic imaging, for example, can be added to current accelerometer based systems to give substantially more information about the crash and the impacting object than possible from the acceleration signal alone.
The side impact anticipatory sensor of this invention can use any of a variety of technologies including optical, radar, acoustical, infrared or a combination of these. The sensor system typically contains a neural network processor to make the discrimination however a simulated neural network, a fuzzy logic or other algorithm operating on a microprocessor can also be used.
With respect to prior art related to this application, reference is made to European Patent Publication No. 0 210 079 (Davis). Davis describes, inter alia, a radar system for use in connection with an airbag deployment apparatus to prevent injury to passengers when impact with an approaching object is imminent. Voltage level inputs representative of the distance between an object and the vehicle, the approach rate of the object with respect to the vehicle, the vehicle speed and driving monitor inputs, e.g., steering angles, turning rates and acceleration/deceleration, are all generated by appropriate detectors, weighted according to their importance to a normal vehicle operators"" sensed safe or danger levels and then the weighted input voltages are summed to provide an xe2x80x9cinstantaneous voltage levelxe2x80x9d. This instantaneous voltage level is compared with a predetermined voltage level and if the instantaneous voltage level falls within a predetermined safe zone, output signals are not produced. On the other hand, if the instantaneous voltage level falls outside of the safe zone, i.e., within a danger zone, then the system can be designed to initiate deployment of the airbag on the additional condition that the vehicle speed is above a predetermined level. For example, the system can be programmed to deploy the airbag when the vehicle speed is between 35 and 204 miles per hour at a time of about 0.2 second prior to impact thereby enabling the airbag sufficient time to fully inflate. (See pages 1-3 of Davis)
As far as structure. Davis includes a radar system that includes an antenna assembly 22, a signal-processing unit 20 and an output monitor 42 (Page 74). Davis relies on a radar signal generated by an antenna 48 in the antenna assembly 22 and which causes a return signal to be produced upon reflection of the radar signal against the approaching object. The return signal is received by a transceiver to be processed further in order to determine the distance between the object and the vehicle and the rate the object is approaching the vehicle. The return signal from the radar signal generated by the antenna is a single pulse, i.e., a single pixel. The elapsed time between the emission of the radar signal by the antenna and the receipt of the return signal by the transceiver determines the distance between the object and the vehicle and based on the elapsed time for a series of radar signals generated at set intervals, it is possible to determine the approach rate of the object relative to the vehicle.
In operation, the approach rate of the object relative to the vehicle, the distance between the object and the vehicle, the vehicle speed as well as other driving parameters are converted to voltage levels. Davis then uses an algorithm to weigh the voltage levels and compare the voltage levels to predetermined conditions for which airbag deployment is desired. If the conditions are satisfied by the results of the algorithm operating on the weighted voltage levels, then the airbag is deployed. In one embodiment, by appropriate manipulation of the voltage levels, false-triggering of the airbag can be prevented for impacts with objects smaller than a motorcycle, i.e., the voltage corresponding to a motorcycle at a certain distance from the vehicle is smaller than the voltage corresponding to a truck for example at that same distance.
Davis does not attempt to recognize any pattern of reflected waves, i.e., a pattern formed from a plurality of waves received over a set period of time, from many pixels simultaneously (light and CCDs) or of the time series of ultrasonic waves. A tree, for example can have a smaller radar reflection (lower voltage in Davis) than a motorcycle but would have a different reflected pattern of waves (as detected in the present invention). Thus, in contrast to the inventions described below, Davis does not identify the object exterior of the vehicle based on a received pattern of waves unique to that object, i.e., each different object will provide a distinct pattern of reflected or generated waves. The radar system of Davis is incapable of processing a pattern of waves, i.e., a plurality of waves received over a period of time, and based on such pattern, identify the object exterior of the vehicle. Rather, Davis can only differentiate objects based on the intensity of the signal.
International Publication No. WO 86/05149 (Karr et al.) describes a device to protect passengers in case of a frontal or rear collision. The device includes a measurement device 12 mounted in connection with the vehicle 11 to measure the distance or speed of the vehicle in relation to an object moving into the range of the vehicle, e.g., another vehicle or an obstacle (FIG. 2). In the event that prescribed values for the distance and/or relative speed are not met or exceeded, i.e., which is representative of a forthcoming crash, a control switch 13 activates the protection and warning system in the vehicle so that by the time the crash occurs, the protection and warning system has developed its full protective effect.
Karr et al. is limited to frontal crashes and rear crashes and does not appear to even remotely relate to side impacts. Thus, Karr et al. only shows the broad concept of anticipatory sensing in conjunction with frontal and rear crashes.
U.S. Pat. No. 4,966,388 (Warner et al.) relates to an inflatable system for side impact crash protection. The system includes a folded, inflatable airbag mounted within a door of the vehicle, an impact sensor also mounted within the door and an inflator coupled to the impact sensor and in flow communication with the airbag so that upon activation of the inflator by the impact sensor during a crash, the airbag is inflated.
Taniguchi (JP 4-293641) describes an apparatus for detecting a body moving around another body, such as to detect a car thief moving around a car. The apparatus includes a detection section 13 supported on a support toll to the roof of the car. Taniguchi states that the detection section 13 may be based on an infrared, microwave or ultrasonic sensor.
This invention comprises an anticipatory sensor system which uses (i) a source of radiant energy either originating from or reflected off of an object or vehicle which is about to impact the side of a target vehicle, plus (ii) pattern recognition means to analyze the radiant energy coming from the soon-to-be impacting object or vehicle to (iii) assess the probable severity of a pending accident and (iv) if appropriate, inflate an airbag prior to the impact so as to displace the occupant away from the path of the impacting object or vehicle to create space required to cushion the occupant from an impact with the vehicle interior. Although the primary area of application of this invention is for protection in side impacts, the invention also provides added protection in frontal impacts by reducing the incidence of injury to out-of-position occupants by permitting a slower inflation of the airbag and displacing the occupant away from the airbag prior to the impact.
The principal objects and advantages of this invention are:
1. To provide for the enhanced protection of occupants in side impacts by determining the probable severity of a pending accident and inflating an airbag prior to the impact to displace the occupant away from the vehicle door.
2. To provide for a method of identifying and classifying an object which is about to impact a vehicle.
3. To adapt pattern recognition techniques, and particularly neural networks, to permit the identification of objects external to an automotive vehicle and the determination of their approach speed and angle of potential collision.
4. To provide a method for assessing the probable severity of a pending accident based on the identification of the class of an object which is about to impact the vehicle plus stored information about the class of such objects such as its mass, strength and attachment to the earth.
5. To provide a method using an ultrasonic system for use in illuminating an object which is about to impact a vehicle and using the reflection of the ultrasonic illumination in combination with a pattern recognition system to identify the object.
6. To determine the approach velocity of an object which is about to impact a vehicle.
7. To identify that a truck is about to impact a vehicle.
8. To identify that an automobile is about to impact a vehicle.
9. To identify that a vehicle is about to impact with a tree.
10. To provide a method using an electromagnetic wave system for use in illuminating an object which is about to impact a vehicle and using the reflection of the electromagnetic wave illumination in combination with a pattern recognition system to identify the object.
11. To provide a method using an the passive infrared electromagnetic waves radiating from an object such as a motor vehicle in combination with a pattern recognition system to identify the object.
12. To provide a system for identifying an object which is about to impact a vehicle in a substantially side impact.
13. To provide a system for identifying an object which is about to impact a vehicle in a substantially frontal impact.
14. To provide a system comprising a variable inflation airbag system where the control of the inflation of the airbag is determined by a prediction of the probable severity of an accident prior to the accident occurring.
15. To provide apparatus for inducing slack into a seatbelt in the event of a side impact to permit the occupant to be displaced sideways in the vehicle.
16. To provide for a single airbag module for protection of the head and torso of an occupant in side impacts.
17. To provide a single airbag module for mounting in the seat back of a vehicle for the protection of the head and torso of an occupant in side impacts.
18. To provide a structure and method for moving the occupant and his seat in the event of a side impact accident to increase the space between the occupant and the intruding object.
19. To provide for an airbag to be deployed external to the vehicle in conjunction with an anticipatory sensor in side impacts.
20. To provide a method using an ultrasonic wave system for use in illuminating an object which is about to impact a vehicle and using the reflection of the ultrasonic wave illumination in combination with a pattern recognition system to identify the object.
To achieve some of these objects, an airbag passive restraint system for protecting an occupant adjacent the door in a side impact in accordance with the invention comprises an airbag arranged to inflate between the door and the occupant and a side impact anticipatory sensor for determining that an accident requiring deployment of the airbag is about to occur prior to the accident. The sensor is arranged to receive waves generated by, modified by or reflected from an object about to impact the vehicle resulting in the accident and comprises identifying and determining means for identifying the object based on a pattern of the received waves and determining whether the identified object will cause an accident requiring deployment of the airbag. The system also includes an inflator coupled to the sensor for inflating the airbag if the sensor determines that an accident requiring deployment of the airbag is about to occur. The identifying and determining means may comprise a neural network trained on data of possible patterns of received waves in conjunction with an identification of the object the received waves have been generated by, modified by or reflected from. In the alternative, the identifying and determining means may comprise a fuzzy logic algorithm or a rule based pattern recognition algorithm. The sensor may be arranged to receive electromagnetic waves or acoustic waves.
Another embodiment of a system for triggering deployment of an airbag passive restraint system in anticipation of an accident between the vehicle and an object approaching the vehicle comprises transmitter means arranged on the vehicle for sending waves toward the object, receiver means arranged on the vehicle for receiving modified or reflected waves from the object and producing a signal representative of the waves, identifying and determining means for identifying the object based on a pattern of the received waves and determining whether the identified object will cause an accident requiring deployment of the passive restraint system and triggering means responsive to the identifying and determining for initiating deployment of the passive restraint system if the identifying and determining means determines that an accident requiring deployment of the passive restraint system is about to occur. The transmitter means may be arranged to transmit electromagnetic waves, such as radar waves, or ultrasonic waves. The identifying and determining means may comprise a neural network trained on data of possible patterns of received waves in conjunction with an identification of the object the received waves have been modified by or reflected from, a fuzzy logic algorithm or a rule based pattern recognition algorithm. The transmitter means may also comprise a laser transmitter and the receiver means may comprise a charge coupled device.
Another embodiment of a system for triggering deployment of an airbag passive restraint system in anticipation of an accident between the vehicle and an object approaching the vehicle comprises receiver means for receiving electromagnetic waves generated, reflected or modified by the object, identifying and determining means for identifying the object based on a pattern of the received waves and determining whether the identified object will cause an accident requiring deployment of the passive restraint system and triggering means responsive to the identifying and determining for initiating deployment of the passive restraint system if the identifying and determining means determines that an accident requiring deployment of the passive restraint system is about to occur. The receiver means may be arranged to receive light waves or infrared waves. As in the embodiments discussed above, the identifying and determining means may comprise a neural network trained on data of possible patterns of received waves in conjunction with an identification of the object the received waves have been generated, reflected or modified by, a fuzzy logic algorithm or a rule based pattern recognition algorithm. The receiver means may comprise a charge-coupled device.
A method for controlling deployment of a passive restraint system in anticipation of an accident with an approaching object is also disclosed and comprises the steps of mounting at least one receiver on the vehicle to receive waves generated by, modified by or reflected from an object exterior of the vehicle, conducting training identification tests on a plurality of different classes of objects likely to be involved in a vehicular accident, each of the tests comprising the steps of receiving waves generated by, modified by or reflected from the object by means of the at least one receiver and associating an object class with data from each test, and generating an algorithm from the training test results, associated object classes and an indication as to whether deployment of the passive restraint system is necessary such that the algorithm is able to process information from the received waves from the at least one receiver, identify the class of the object and determine whether deployment of the passive restraint system is necessary. During operational use, a plurality of waves generated by, modified by or reflected off an object exterior of the vehicle are received by means of the receiver(s) and the algorithm is applied using the received waves as input to identify the object exterior of the vehicle and determine whether deployment of the passive restraint system is necessary. At least one transmitter may be mounted on the vehicle to transmit waves toward the object exterior of the vehicle such that the waves are reflected off or modified by the object exterior of the vehicle and received by the receiver(s).
In some implementations, the sensor system may include a variable inflation rate inflator system for inflating the airbag(s). Such an inflator system comprises inflator means for releasing a gas into the airbag(s), a first anticipatory crash sensor for determining that a crash requiring an airbag will occur based on data obtained prior to the crash and, upon the making of such a determination, triggering the inflator means to release gas into the airbag(s) to thereby inflate the same at a first inflation rate, a second crash sensor for determining that a crash requiring an airbag will occur or is occurring and, upon the making of such a determination, affecting the inflator means such that an additional quantity of gas is released thereby into the airbag(s) to thereby inflate the same at a second inflation rate greater than the first inflation rate.
The inflator means may comprise a first and second inflator structured and arranged to produce gas and direct the gas into the airbag(s) and which are independent of one another such that the first inflator may be triggered by the first anticipatory sensor without triggering of the second inflator and the second inflator may be triggered by the second crash sensor without triggering of the first inflator.
In conjunction with the variable inflation rate inflator system described above, a method for providing a variable inflation rate of the airbag(s) is also envisioned. Such a method would entail determining that a crash requiring an airbag will occur based on data obtained prior to the crash, e.g., by an anticipatory sensor, and upon the making of such a determination, triggering an inflator to release gas into the airbag(s) to thereby inflate the same at a first inflation rate, determining in another manner that a crash requiring an airbag will occur or is occurring and, upon the making of such a determination, affecting the inflator such that an additional quantity of gas is released thereby into the airbag(s) to thereby inflate the same at a second inflation rate greater than the first inflation rate. Thus, the airbag is inflated either at the first inflation rate, i.e., if the conditions do not warrant a more powerful inflation, or the second, higher inflation rate, i.e., if the conditions warrant an inflation of the airbags as rapidly as possible. The inflator may comprise a first and second inflator each of which produces gas and directs the gas into the airbag(s) and which are independent of one another such that the first inflator may be triggered by the initial determination of a crash requiring the airbag deployment without triggering of the second inflator and the second inflator may be triggered by the subsequent determination of a crash requiring airbag deployment without triggering of the first inflator.
Furthermore, the anticipatory sensor system described above may be used in conjunction with an airbag passive restraint system for protecting an occupant sitting in the seat adjacent the side door. Such a restraint system may comprise one or more airbag(s) arranged to be inflated between the occupant and the side door, sensor means for detecting that a crash requiring deployment of the airbag(s) is required, inflator means for releasing a gas into the airbag(s) to inflate the same and which are coupled to the sensor means and triggered thereby to release gas into the airbag(s) in response to the detection by the sensor means of a crash requiring deployment of the airbag(s), a seatbelt coupled to the seat for restraining the occupant on the seat and occupant displacement permitting means arranged in connection with the seat for permitting the occupant to be displaced away from the side door upon inflation of the airbag(s) and thereby increase the space between the occupant and the side door.
The occupant displacement permitting means may take a number of different forms all of which serve to enable the occupant to be displaced away from the side door, and if applied in conjunction with an airbag inflating between the side door and the occupant, the inflating airbag may provide a force which serves to actually displace the occupant away from the side door. One embodiment of the occupant displacement permitting means comprises slack introduction means arranged in connection with the seatbelt for introducing a controlled amount of slack into the seatbelt. Alternatively, the occupant displacement permitting means comprise means for changing an anchorage point of the seatbelt from a first anchorage point to a second anchorage point upon inflation of the airbag, both of which may be arranged on a side of the seat away from the side door. The second anchorage point is permanently fixed to the vehicle whereas the first anchorage point is defined by a strip permanently fixed to the vehicle, a first member connected thereto, and a second member having a first position connected to the first member in which the seatbelt is retained at the first anchorage point and a second position apart from the first member in which the seatbelt is not retained at the first anchorage point. Separation means, such an explosive bolt assembly, are coupled to the sensor and move the second member from the first position to the second position so that the seatbelt is no longer retained at the first anchorage point and the displacement of the occupant is not hindered by the seatbelt.
In another embodiment, the system includes mounting means for mounting the airbag adjacent the occupant and the sensor is an anticipatory sensor structured and arranged to detect that a crash requiring deployment of the airbag is required based on data obtained prior to the crash such that the inflator means are triggered to release gas into the airbag prior to the start of the crash. In this case, the occupant displacement permitting means are operatively associated with the anticipatory sensor and the seat to increase the space between the occupant and the side door upon inflation of the airbag. The occupant displacement permitting means may comprise means for laterally displacing the seat away from the side door such as one or more rail mechanisms, each including a first member having a guide channel arranged in connection with the seat or the vehicle and a second member positioned for movement in the guide channel arranged in the other of the seat and the vehicle. Alternatively, the occupant displacement permitting means comprise means for rotating the seat about the vehicle roll axis, possibly also by rail mechanisms, means for rotating the seat about the vehicle yaw axis or means for lifting the seat vertically. The seat lifting means may comprise a first plate attached to the seat, a second plate attached to the vehicle and hingedly attached to the first plate, and a clamp for releasably retaining the first plate in connection with the second plate.
Any of the airbag passive restraint systems described herein may be used in conjunction with the variable inflation rate inflator system described above, and may be used in conjunction with one another to optimize protection for the occupant.
In conjunction with the airbag passive restraint system for protecting an occupant sitting in the seat adjacent the side door described above, the present invention also envisions a method for protecting such an occupant. Such a method would include the steps of detecting that a crash requiring deployment of one or more airbags is required, if so, releasing a gas into the airbag(s) to inflate the same and then in before, during or after the gas is released into the airbag, causing the occupant to be displaced away from the side door upon inflation of the airbag(s) to thereby increase the space between the occupant and the side door. The manner in which the occupant is caused to be displaced away from the side door may take any of the forms described herein.
Other methods for protecting an adjacent occupant in a side impact within the scope of the invention includes the steps of mounting an airbag module comprising a housing and an inflatable airbag arranged within the housing in combination with a seat back, detecting that a side impact requiring deployment of the airbag is required based on data obtained prior to the crash, e.g., by an anticipatory sensor, and then inflating the airbag in the event a side impact requiring deployment of the airbag is detected prior to the start of the impact.
Another possible method entails the use of an externally deployable airbag system for protecting the occupant in a side impact with an impacting object. This method would include the steps of determining that a side impact requiring deployment of an airbag outside of the vehicle between the side of the vehicle and the impacting object is required based on data obtained prior to the crash, and then inflating the airbag in the event a side impact requiring deployment of the airbag is detected.